Hydraulic debarking method



Nov. 15, 1949 F. H. SWIFT HYDRAULIC DEBARKING METHOD 4 Sheets-Sheet 1Filed Oct. 3, 1946 INVENTOR. FRANK Hv SWIFT ATTORNEY Nov. 15, 1949 F. H.SWIFT 2,483,041

HYDRAULIC DEBARKING METHOD Filed Oct. 3, 1 946 1 4 Sheets-Sheet 2INVENTOR. FRANK H. SWIFT ATTORNEY Nov. 15, 1949 F. H. SWIFT HYDRAULICDEBARKING METHOD 4 Sheats-Sheet 3 Filed Oct. 3, 1946 INVENTOR. FRANK HpSWIFT ATTOR N EY Nov. 15, 1949 F. H. SWIFT 2,488,041

HYDRAULIC DEBARKING METHOD Filed Oct. 5, 1946 4 Sheets-Sheet 4 INVENTOR.FRANK H SWIFT ATTORNEY and 15.1949- p '2,4ss.'o4r HYDRAULIC namaxnvoME'rnon rrmkn. Swift, Portland,'0reg., assignorto Crown QZeilerbachCorporation, San Francisco,

corporation of Nevada Application October a, 1946, Serial No. 700,998

This application is a continuation in partof my pending application,serial No. 538,360, flied June 2, 1944, entitled Hydraulic barker forslabs. now U. S. Patent No. 2,413,341, issued-December 31, 1946.Reference is also to be made to my co-pending application, Serial No.700,999 on Hydraulic barkenflled under even date and relating to similarsubjectmatter.

The present invention relates to the removal of bark from logs, cants orslabs by high velocity jets of water.

Various devices which are at present being employed for the hydraulicdebarking of logs have shown that a high velocity jet of water, if,properly directed against the bark surface of a log, will remove thebark in its path satisfactorily without the aid of any mechanicaldebarking means. Some of these devices, however, require the logs to berotated as well as moved longitudinally during the debarking and areless satisfactory on that account, since the necessity for mounting thelogs for rotation and for rotating them at the proper rate under varyingcircumstances, present certain difliculties and problems; andfurthermore, these devices cannot be used for cants or slabs. Otherhydraulic debarking devices necessitate the simultaneous employment of aconsiderable number of debarking jets. and thus require the utilizationof a large volume of water under high pressure in order to enable thedebarking to proceed with sufilcient speed to be practicable.

The object of the present invention is to provide an improved method tobe employed in hydraulic debarking in which each hydraulic jet will beutilized to remove the bark over a greater area.

Another object of this invention is to provide a practical method fordebarking a log with a minimum number of hydraulic debarking nozzleswith or without rotation of the log.

An additional object is to provide an improved method of employinghydraulicdebarking nozzles which can be utilized for cants and slabs aswell as whole logs, and by which method each nozzle will remove the barkin a broad, longitudinally-extending strip on a log, cant or slab.

The accompanying drawings illustrate a. simple' means which I havedeveloped for carrying out my method; and my improved method will be 1easily understood from a brief description of the operation of theparticular means illustrated in the drawings. Various other-means couldof course also be employed in a similar manner as will be evident later.a l

3 Claims. (Cl. 144-309 CaliL, a

Referring'to the drawings:

Fig.1 is a top plan view of a single debarking nozzle assembly, which isassumed to be located above a log or cant or slab;

Fig; 2 is a front elevation of the same;

Fig. 3 is a sectional side elevation taken on line 3-3 of Fig. 1; r

Fig. 4 is a fragmentary top planview and partial plan section drawn to alarger scale;

Fig. 5 is a more or less diagrammatic elevation illustrating thedebarking of a log by my method.

Fig. 6 is a similar elevation illustrating the de barking of a slab.

Fig. 7 is a diagrammatic plan view of the path described on thesurfaceof a log by the jet from a single nozzle assembly as illustratedin Figs. 1 to 5, when the log is stationary;

Fig. 8 is a similar diagrammatic plan illustrating the resulting path ofthe same nozzle jet on the log surface when the log is movedlongitudinally at a proper rate of speed;

Fig. 9 illustrates diagrammatically a modified manner in which my methodmay be employed on a'rotating log;

Fig. 10 is a diagrammatic representation of the debarking of a strip ona rotating log by a single hydraulic nozzle in the employment of mymethod in such modified manner; and

Fig. 11 is a fragmentary elevation of one of the nozzle assembliesshowing aslight modification in which a double nozzle, or a pair ofnozzles moving in unison, can be used for producing the jet path on thebark surface which composite jet path carries out my method.

Referring first to Figs. 1 to 4 inclusive, it indicates a stationaryplatform or deck which is securely supported on a suitable frame (notshown) at a predetermined location with respect to the logs, cants orslabs to be debarked. An electric motor II, suspended from the platformIll, rotates a horizontal shaft !2 on the end of which a drive wheel i3is secured. The perimeter of the wheel i3 is formed with a speciallyshaped cam groove [4 (Fig. 3), the nature and purpose of which will besubsequently explained.

A shaft i5 is rotatably supported ina pair of bearing blocks l6 and i1mounted on the platform iii. A nozzle housing l8, the shape andconstruction of which are shown. mostclearly in Fig. 4, is secured tothe end of the shaft i5. Preferably the housing I 8 is formed with anex? ternal boss l9 into which the end of the shaft I5 is fitted and towhich it is firmly secured in any suitable manner. The housing i8 has asupports this pipe branch 20 of the housing |8.,

The nozzle, designated in its entirety by the reference character 24,has a horizontal upper portion 25 which is rotatably mounted in thehousing I3. A pluralityof ports 26 (Fig. 4), in

this upper portion of the nozzle, connect with the interior chamber 21of the housing. Thus water from the supply pipeline 22 passes throughthe housing branch 2n into the housing chamber 21 and thence into thenozzle through the ports 26. Suitable packing glands 28 are providedaround the nozzle on the exterior of the housing l8 and are held inplace in the usual manner by locking rings 29 provided with externalflanges which are connected by bolts to adjacent flanges formed atcorresponding ends of the housing.

From the description thus far it will be apparent that while the nozzleis mounted to rotate in the housing l8 on one axis, the entire housing,and with it the nozzle, is mounted to rotate on another axis, the twoaxes being normal to each other. The nozzle 24 terminates in adischarging tip 30 by means of which a debarking jet of predeterminedshape and dimension is directed against the surface to be debarked.

A U-shaped metal strap member 3| has both ends formed with sleeves 32which are keyed or otherwise rigidly secured on the shaft l5. On themember 3|, at the bottom, is mounted a roller 3| (Fig. 3), which extendsinto the cam groove l4 on the perimeter of the drive wheel l3 and actsas a cam follower. With the rotation of the wheel |3 the cam follower3|, and with it the bottom of member 3|, will be moved towards and awayfrom the motor II, as apparent from Fig. 3. In other words, member 3|will be rocked back and forth as the wheel l3 rotates. The rocking ofmember 3| will cause a rocking of the shaft l5 to which it is rigidlysecured and the rocking of shaft IS in turn will cause the entirehousing i8 and thus the entire nozzle assembly 24 to be rockedsimilarly.

The cam groove M has two identical mainsloping sections, indicated by a:in Fig. 3, and two short and more abruptly and oppositely curvedsections 1/ between the main sections 1:. Thus with each half rotationof the wheel l3 the nozzle tip 30, as viewed in Fig. 3, will be movedgradually to the right and then quickly moved back to the left to theoriginal position.

The rotation of the wheel l3 also produces another movement of thenozzle through the intermediary of a connecting rod 33. This connectingrod is shown more clearly in Figs. 1 and 2. One end of the connectingrod 33 is connected to thedrive wheel l3 preferably through theintermediary of a universal joint, and the other end is similarlyconnected to the nozzle 24. Thus with each rotation of the drive wheel|3 the nozzle 24 is swung back and forth in the nozzle housing l8, butat the same time the nozzle housing i8 is also rocked on its separateaxis by the member 3| as previously described. The eilects of these twocomponent directions of reciprocating movement on the resultant path ofthe Jet from the nozzle will be described with reference to Figs. 7 and8.

In Fig. 7 it is assumed for the purpose of illustration that the log L,againstthe of which the let from the nozzle'tip is impinged. istemporarily stationary while the nozzle is being driven by the rotationof the wheel II in the manner previously described. The location of theconnection between the drive wheel l3 and the connecting rod 33 is soarranged with respect to the sectionsa: and 1 of the cam groove H on thewheel l3 that one of the sections 11 (Fig. 3), will engage the roller 3l" of "member 3| whenever the wheel and rod connection is at either endof the longitudinal diameter of its circular path.

the rotation of the wheel l3 and the operation of the crank shaft 33cause the nozzle tip to swing transversely with respect to the log axis,the travel of the cam follower or roller 3| in one of the main sectionsa: of the cam groove of wheel l3 will also cause the nozzle tip to moveslightly longitudinally with respect to the log axis. Then. when theconnecting rod 33 is about to reverse the direction of transverse swingof the nozzle tip, the travel of the cam follower on the next section 1/of the cam groove will cause the nozzle tip to move quickly backlongitudinally with respect to the log axis. Thus, referring to Fig. 7,let it be assumed that the center of the jet from the nozzle strikes thelog at some point A when the connecting rod has reached the limit of itstravel in one direction. While the connecting rod causes the nomle to'swing transversely with respect to the log axis, one of the cam groovesections a: causes the nozzle to move longitudinally with respect to thelog axis. As aresult of these two component forces acting on the nozzlethe jet from the nozzle will travel in the oblique ath A-B on thesurface of the log. When the center of the jet reaches the point B,however, the engagement of the cam follower 3| with one of the sections1 of the cam groove I4 results in movement of the jet quickly to thepoint C. Next, the moving of the nozzle by the connecting rod and theengagement of the cam follower in another cam groove 2: will result inthe jet traveling the transverse oblique path from C to D. Finally, whenthe center of the jet reaches the point D the engagement of the camfollower with another section 1 of the cam groove causes the center ofthe jet to move again to the point A, and the jet proceeds to repeat itssame travel. The amount of slope of the sections .1: and 1 in the camgroove I4 is made such that the tilting of the nozzle jet longitudinallywith respect to the log axis will in each instance be approximatelyequal to thewidthof the let longitudinally as it strikes the logsurface.

If, instead of remaining stationary during the movements of the nozzlejet as previously described, the log L is moved longitudinally in thedirection of the arrow M in Fig. 8, and if the rate of longitudinaltravel of the log is constant and corresponds to the width of the nozzlejet with each transverse swing of the nozzle produced by the connectingrod 33, the jet paths A-B and 0-D will be normal to the log axis andwill ad- Join each other, as illustrated in Fig. 8, and, with thecontinued travel of the log and transverse swinging of the nozzle, thebark will be removed from the log surface in a broad, longitudinal stripequal in width approximately to the distance A-B. Thus by my method, thejet from a single nozzle can be used to cover a broad, longitudinalstrip on a log, without passing over any portion of the bark surfacetwice and without any rotation of the log. Thus any wasting of water isavoided. the highest possible eiilciency is obtained from each nozzlejet, and the problem of rotating the log is eliminated.

By employing a'pluralityof such nozzle assemblies, thus, for example,arranging five or six similar nozzle assemblies insymmetricallocationabout the log and equidistantfrom the log surface, it.is possible to .debark the entire log surface during ;a single travelof the log longitudinally without any rotation of the log. In Fig.Iindicate such an arrangement of 6 nomleassemblies employing nw method.Due to the fact that the jet from each nozzle debarks a broad,longitudinally-extending strip on the surface of the log, comparativelyfew nozzle assemblies are required, and forsmaller diameter logs evenless than six nozzle assemblies will suflice for debarking the entirelog surface as the log, supported by or such thickness as to require thedebarking jets to go over the surface twice for complete removal of thebark, all that would be necessary with my method would be to reducetherate of longitudinal travel'of such logs, cants or slabs withoutchanging the nozzle speed.

It would of course be possible, with my method, to have the nozzleassemblies mounted on a carriage and have the entire carriage in turnarranged to travel longitudinally along the log, cant or slab. However,since it is a relatively simple matter to move logs longitudinallycompared to the difliculty of mounting them for rotation and rotatingthem, I believe in most cases it will be found preferable to have theframe, on which the nozzle assemblies are mounted, remain stationary,

As previously mentioned, various devices, other than the particular onewhich I have shown, could be used for carrying out my improved method.All that is required is to have the jet from each nozzle move in rapidstrokes, traveling in the composite directions described, while the 6are well known in the art and need not be described here.

Under such modified conditions the debarking nozzle assembly-4| of Fig.9 is-tumed 90 from the position previously described so that the majorswings of the nozzle will be only slightly diver-,

, allel adjacent paths 43 indicated in Fig. 10. When the strip.42 hasbeencompleted around the log the log is advanced longitudinally adistance approximately equal to. the WidthOf the strip 42. If the rateof rotation of the log corresponds to v the width of the path of thenozzle jet in the strip 42 with each major swing of the nozzle it willbeapparent from the explanation previously given that the jet willcoverthe entire area in each lateral strip 42 without passing over anyportion I of the strip twice.

If, instead of having the longitudinalmovement of the rotatin log occurintermittently, the log moves steadily longitudinally as it rotates,such movement of the log also being well known in other types ofdebarking machines, the stripv 42 in which the debarking occurs wouldextend spirally'over the log surface but there would be no further,change in the employment of my method.

I have heretofore referred to each debarking nozzle assembly asembodying a single nozzle and corresponding single jet. It would,however, be

, possible to substitute a double nozzle or even a desired relativelongitudinal movement of the long, cant or slab takes place with respectto. the support on which the nozzle assemblies are mounted.

Thus far I have described the carrying out of my method in the debarkingof a log when relative longitudinal movement is given to the log withrespect to the barkerthat is, either when the log is movedlongitudinally through the barker or when the nozzle assembly orassemblies are moved longitudinally along the log-but without anyrotation of the log. However, my method can also be satisfactorilyemployed when the log is mounted for rotation and a single debarkingnozzle assembly can be used for an entire log under such conditions invarious ways. For example, in Figs. 9 and 10 the log 40 isassumed to bemounted for rotation by any suit able means inaddition to being mountedfor longitudinal movement. It is assumed also, merely for purpose ofillustration, in Figs. 9 and 10, that the longitudinal movement of thelog is arranged to occur intermittently, thus at the end of eachrotation. Various means for mounting logs for plurality of nozzlesmoving in unison in each assembly and, so placed that their jets wouldcombine to form a single path on the bark surface. Such a modificationis shown in Fig. 11, in which a double nozzle 50 is shown in place ofthe single nozzle tip 30 of Fig. 3. The two jets II and 52 from thedouble nozzle 50 combine. on the surface of the log 53 to form a singlepath 54 equal approximately to the combined widths of .the two jets. Thepath 54' then follows the forwardly oblique transverse coursespreviously described and thus in principle there would be no change inmy method. With such a double nozzle a drive wheel 55 having a widerperimeter and a cam groove 56 producing greater movement of the shaft I5would be employed.

I claim:

1. In the hydraulic debarking of a log, the method of removing bark in awide strip with a hydraulic jet engaging the log in a path in saidstrip, said method comprising providing for a relative movement betweenthe surface of said log and the debarking apparatus during the debarkingof the strip, causing said jet to move back and forth in rapid strokestransverse with respect to said strip and thus causing said path of saidjet to follow transverse courses across the strip, directing saidstrokes of said jet so that each transverse course of said path will bein a forward oblique direction with respect to said relative'movement ofthe surface of said log but so that the position of said path at theteriniriation of each stroke will be not more than the width of saidpath ahead of the position of said path at the beginning of that stroke,moving said jet in a direction opposite said relative movement of thelog surface at the end of each stroke so that said path will be movedback a distance not exceeding the width of said path, and restrictingthe said relative movement of said log surface to an amount notexceeding the width of said path for each stroke.

2. In the hydraulic debarking of a log or cant, the method of removingbark in a wide, longitudinally-extending strip with a single hydraulicjet engaging the log or cant in said strip. said method consistinginproviding a constant longitudinal movement of said log or cant duringthe debarking of the strip, causing said jet to move back and forth inrapid transverse oblique strokes with reference to the strip to bedebarked so that the path of said jet on the bark .will followtransverse oblique forward-extending courses, directing said strokes sothat the position of said path at the end of each course will beapproximately the width of the path longitudinally ahead of the positionof the path at the beginning of that stroke, moving said jet in adirection opposite said longitudinal movement at the end of each strokesumciently so that said path will be moved back in a correspondingopposite direction a distance equal approximately to the width of saidpath before said path follows the next oblique course, and having thelog or can't move longitudinally a distance approximately equal to thewidth of said path for each of said transverse strokes, whereby said jetwill cover the entire bark surface along a relatively broad stripwithout passing over any portion of the strip twice and thus enable mosteflicient coverage to be obtained from the jet.

3. The improved method of removing bark from the surface of a log orcant by hydraulic debarking apparatus, which method consists inprovidingmeans for causing a bark-removing Jet from a nozzle or nozzles to beimpinged against said surface, providing for a relative'movement in aconstant direction between said surface and said apparatus, moving saidjet so as to cause the path of said jet to follow equal transversecourses across a wide strip on said surface in a forward obliquedirection with-respect to the direction of said relative movement ofsaid surface, limiting said forward oblique direction of said courses sothat the position of said jet path at the termination of each transversecourse will required for each transverse course.

FRANK H. SWIFT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 599,846 Judge Mar. 1, 18981,969,914 Swigert Aug. 14, 1934 2,393,978 Edwards Feb. 5, 1946

